The present invention relates generally to wave generation and, more particularly, to a pneumatic wave generation system for generating waves in a pool.
Wave generation systems for artificially creating waves in liquids are well known and find utilization in a range of applications. One such application is for the creation of waves in a swimming pool for recreational purposes. Swimming pools with wave-making equipment are in common use and have found widespread acceptance in numerous amusement or aquatic-theme parks throughout the world. In some applications, pools with wave making equipment serve alternatively as a venue for competitive swimming events. Aquariums provide another market for wave generation systems.
In such applications, various mechanical and pneumatic devices and apparatus have been utilized to engage and displace water at one end of a pool to create a surface wave pattern. A conventional wave generating system may house at a deep end of a pool multiple caisson chambers. A ventilator space is provided within each caisson above the surface of water therein. A source of forced air capable of effecting aspiration by applying compressed air to the space above the water surfaces in the chambers is supplied by a conduit system. When the caissons are actuated with pressurized air, the water levels therein are driven down, out a lower caisson passageway, and into the pool, thereby creating the intended wave disturbance.
The Raike U.S. Pat. No. 4,812,077 discloses a wave generator of the mentioned type. A pneumatic system includes a motor-driven fan that communicates selectively with duct lines to the caissons through a pair of two-position air directional valve assemblies. Selective actuation of the two air directional valve assemblies between caisson chambers allows the wave generator to create alternative wave shapes and patterns, augmenting the utility of the installation and its amusement value to users.
While working well, existing wave generators have certain common deficiencies and inefficiencies. First, the housings in which the caissons are deployed are relatively large and rise above the pool deck at the deep end an undesirably distance. As a result, steps must be incorporated into the pool deck in order to allow users to traverse the perimeter of the pool. In addition, the high housing of the caissons at the deep end of the pool may interfere with the placement of competitive starting blocks in the pool, and thereby defeat or inhibit the capacity of the pool to serve as a venue for competitive swimming meets. Finally, a high caisson housing is aesthetically displeasing. A wave generator providing acceptable functional utility yet having a lower vertical height compatible with providing a uniform deck area surrounding a pool is, accordingly, desired by the industry.
The size of the caisson housing in conventional wave generators, however, is a function of the relatively large air displacement required by state of the art caissons deployed therein. Since the cycle time for charging each caisson with pressurized air, discharging the generated wave from the caisson, and exhausting the caisson, is significantly short, on the order of two seconds or less, a relative large and excessive volume of pressurized air must be quickly injected into each caisson in order to correspondingly effect a quick movement of the water level downward. Currently, in state of the art wave generating systems, more air is used than optimally required because of short cycle time demands and system losses. It would, accordingly, be an advantage to reduce the amount of air required to charge a caisson in wave generating systems. Such a reduction in the volume of required air would reduce the requisite size of the caisson air chamber, allowing for a reduction in vertical height. Additionally, a reduction in the volume of air required to charge wave generating caissons would enhance system efficiencies and allow the use of smaller, more energy efficient fan systems.
In order to supply the quantity of (excessive) pressurized air into a caisson, current systems employ a high capacity fan system that distribute the air to caissons via an extensive network of large conduits or ducts. Such fans are expensive, noisy in their operation, and have a high power utilization rate, resulting in an undesirable increase in the cost of operating the wave generator. In addition, the duct network feeding air to the caissons from such large, inefficient fans include a number of relatively severe conduit bends. Such bends represent interference to the efficient flow of air to the caissons and, therefore, add to the inefficiency of the overall system. Accordingly, the industry is further in need of a wave generator that can utilize quiet, low power fan units that efficiently distribute pressurized air to the caissons through an efficient, relatively bend-free conduit system.
In conventional wave generators, the large volume of pressurized air necessary to rapidly charge a caisson is injected into the caisson by a nozzle positioned above the water level. The pressurized air, thus, is not evenly distributed over the surface of water within the caisson and its focused entry into the water tends to cause turbulence as the water level is pressured downward. Undesirable turbulence degrades the quality of the generated wave and represents a system loss of pneumatic efficiency that is likewise undesirable. Thus, the need exists for a wave generator that can equally distribute and disperse pressurized air over the surface of water within a caisson so as to result in minimal losses from turbulence and maximum pneumatic efficiency.
The Raike U.S. Pat. No. 4,812,077 discloses a pair of two-position directional valve assemblies, each capable of delivering compressed air into adjacent caissons alternatively. Each valve assembly swings to service two adjacent caisson compartments. A swinging cylinder sleeve provides fast operational speed and requires a low level of energy to actuate and brake. The valve assembly also allows the wave generator to be programmable, and the four caissons serviced by the two valve assemblies can be energized in a range of sequences. The shape and pattern of waves, as a result, may be varied and the recreational value of the wave generating system is thereby enhanced. While working well, it is desirable in certain applications to provide each caisson with its own, dedicated air injection nozzle. The nozzle should provide for efficient injection of air into its respective caisson. A valve system is further required to operatively close the nozzle during the exhaust portion of the cycle or when the actuation of the nozzle is not needed for the particular wave desired. Such a nozzle and valve arrangement should work in mutual cooperation and be economical to manufacture and maintain.
It is, therefore, an object of the present invention to provide a pneumatic wave generator having a novel air dispersion apparatus for equally distributing air pressure within a caisson.
It is another object to provide a pneumatic wave generator requiring a relatively low caisson housing.
It is yet another object of the invention to provide a pneumatic wave generator having an air dispersion apparatus for facilitating rapid, even dispersion of air pressure against water surface within a caisson.
Another object of the invention is to provide a pneumatic wave generator that requires a relatively low power compressed air source.
A further object of the invention is to provide a pneumatic wave generator and associative pool in which the decking surrounding the pool is uniform.
Yet a further object of the invention is to provide an improved injector nozzle for a pneumatic wave generator.
Still a further object of the invention is to provide an injector nozzle for a pneumatic wave generator having an integral shut-off valve assembly incorporated therein.
Another object of the invention is to provide an injector nozzle for a pneumatic wave generator having a rapid injection/exhaust cycle and a low power utilization rate.
A further object of the invention is to provide an injector nozzle for a pneumatic wave generator that is economical to produce and install, and economical to operate.
Another object of the invention is to provide an injector nozzle for a pneumatic wave generator having in integral shut-off valve responsive to operative movement of the injector nozzle.
The present invention has as a further object the achievement of an air distribution system for a wave generator that incorporates a relatively small, quiet, energy efficient fan and a low loss air delivery conduit network.
An additional object is to provide a wave generator having an air generation and distribution system that is economical to manufacture and operate.
These and other objects of the present invention, as well as the advantages thereof over existing wave generator assemblies, which will become apparent from the description to follow, are accomplished by the improvements hereinafter described and claimed.
In general, the present invention provides a pneumatic wave generator comprising multiple, relatively low, caissons. An associative injector nozzle assembly communicates with each caisson and delivers air to drive the water level within the caisson downward. The nozzle assembly includes a nozzle pivotally mounted to a support frame and pivotal between an open position in which air within the nozzle is free to enter the caisson and a shut-off position in which the flow of air from the nozzle is inhibited. A butterfly valve is integrally mounted within the nozzle and moves therewith between the first and second nozzle positions. The butterfly valve allows air to pass in the open position. Upon exhausting the caisson, the valve within the nozzle will move by an air cylinder or a linear actuator and close the butterfly valve. The force required to pivot and brace the nozzle is modest and the butterfly valve integrally mounted within the nozzle achieves a reliable, repeatable fit between the nozzle internal walls.
A further aspect of the invention is to provide a dispersion grate mounted across a top portion of each caisson. The grate is configured having an array of through-bores therein and vane flanges that directionally fan out to direct input air across the surface of the dispersion grate. Sidewalls of the grate through-bores are further configured to intercept the air delivered by the vane flanges and evenly direct the air downward through the grate to the water surface therebelow. The dispersion grate thus serves to efficiently distribute input air into the caisson across the surface of the water so that the water surface may be pressured downward in an efficient, rapid manner. The volume of air required to effect formation of a wave is thereby reduced, allowing for a commensurate reduction in the size of the motor providing the supply of air. The efficiency so attained allows for a reduction in the requisite height of the air chamber above the water level within each caisson. The reduction in height of the caisson in turn allows the caisson housing to assume an even, coplanar relationship with the decking surrounding the pool and eliminates the shortcomings discussed above that are endemic to state-of-the-art, multi-level wave generating pool decking.
Finally, the a further aspect of the wave generator system of the present invention is providing an air generation and distribution system including a horizontally mounted impeller fan, and an air feed conduit to each of the caissons having relatively few bends. The impeller fan efficiently draws air down into the feed conduit from above, and generated noise from the fan is generally directed upward, minimizing ambient noise levels. The system further provides an air distribution conduit network that has relatively few bends that would otherwise create an impediment to the efficient delivery of air from the fan to the caissons.